Question

I need help with these. Please show workings​

Answer 1

Answer:

Imp = 25 [kg*m/s]

v₂= 20 [m/s]

Explanation:

In order to solve these problems, we must use the principle of conservation of linear momentum or momentum.

1)

$(m_{1}*v_{1})+(F*t)=(m_{1}*v_{2})$

where:

m₁ = mass of the object = 5 [kg]

v₁ = initial velocity = 0 (initially at rest)

F = force = 5 [N]

t = time = 5 [s]

v₂ = velocity after the momentum [m/s]

$(5*0) +(5*5) = (m_{1}*v_{2}) = Imp\\Imp = 25 [kg*m/s]$

2)

$(m_{1}*v_{1})+(F*t)=(m_{1}*v_{2})\\(0.075*0)+(30*0.05)=(0.075*v_{2})\\v_{2}=20 [m/s]$

Answer 2

Hey There!

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Question 1)

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DATA:

Force = F = 5N

time = t = 5 seconds

mass = m = 5 kg

momentum = p = ?

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SOLUTION:

IMPULSE FORCE:

The force which acts for a very short period of time is called impulse force. It is given by,

                                      I = F x t

Where,

              I is impulse

              F is force

              t is time till which force is exerted

The impulse experienced by the object equals the change in momentum of the object. In equation form,

                                    F x t = M x ΔV

 So,

                     F x t = Final momentum - initial momentum

                     F x t = final momentum - (0)

initial momentum is zero because the object was initially at rest.

                     Final momentum = 5 x 5

                     Final momentum = 25 $kgms^{-1}$

So B is the answer

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Question 2)

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DATA:

Force = F = 30 N

time = t = 0.05 seconds

mass = m = 0.075 kg

V = ?

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SOLUTION:

impulse force is given by,

                                      I = F x t

Where,

              I is impulse

              F is force

              t is time till which force is exerted

The impulse experienced by the object equals the change in momentum of the object. So,

                                    F x t = M x ΔV

 So,

                     F x t = Final momentum - initial momentum

                     F x t = final momentum - (0)

Since it was at rest initially, initial momentum is zero.

Momentum is given by,

                                p = m x V

where,

           p is momentum

           m is mass

           v is velocity

So,

                 F x t = m x V

Rearrange the equation,

                                        V = $\frac{Fxt}{m}$

                                        $V = \frac{(30)x(0.05)}{0.075} \\\\V = 20 m/s$

So C is the answer

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Best Regards,

'Borz'